Exclusion Principle - why doesn't degneracy balance weight?

[AlfaFoxtrot]

Fairly simple question, I just couldn't think of a suitable explanation for it.

In white dwarfs, neutron stars etc gravity is balanced by high outward pressure of fermions, which are in a confined space, so have v. high velocities. My question is, if you placed a heavy weight on an ordinary chair, it doesn't go straight through the chair because of the electrostatic repulsion of electrons, but also the PEP repulsion as they are being squeezed closer together. So why does a chair break when a weight too heavy is put on it? Surely the PEP repulsion just increases as electrons are moved closer together, thereby balancing the weight and not putting any stress on the chair?

I'm sure the explanation is dead simple, and I'm currently thinking it's a equal-opposite reaction kind of thing. Thanks in advance for any replies...

 

[member 553083]

The reason why a chair breaks when a weight too heavy is placed on it is because the electrons in the chair are not able to resist the pressure of the weight due to their limited mass. The Pauli Exclusion Principle (PEP) does increase the repulsive force between the electrons, but it is not enough to oppose the weight which produces a net force that is greater than the force of the PEP repulsion. This net force causes the chair to eventually break.